Method For Connecting Components

ABSTRACT

The invention relates to a method for the connecting of components, namely for the connecting of at least one pipe-shaped or rod-shaped component with a wall-type component, with the following steps: a) providing a wall-type component ( 11 ), whereby the wall-type component ( 11 ) comprises a sandwich-type structure of two plate-shaped or pipe-shaped elements ( 12, 13 ) with a layer ( 14 ) of an expandable foamable metal material positioned therebetween; b) providing at least one pipe-shaped or rod-shaped component ( 10 ); c) introducing at least one opening in the wall-type component ( 11 ) for the receiving of the or each pipe-shaped or rod-shaped component ( 10 ); d) inserting of the or each pipe-shaped or rod-shaped component ( 10 ) in a corresponding opening of the wall-type component ( 11 ); e) heating of the arrangement of the wall-type component ( 11 ) and the or each pipe-shaped or rod-shaped component ( 10 ) with foaming-up expansion of the expandable foamable metal material for the connecting of the or each pipe-shaped or rod-shaped component ( 10 ) with the wall-type component ( 11 ).

The invention relates to a method for the connecting of components, namely for the connecting of at least one pipe-shaped or rod-shaped component with a wall-type component.

In the production or fabrication of especially heat exchangers, components with complex geometries must be connected with one another. Thus, in the fabrication of heat exchangers, pipe-shaped components embodied as lance pipes, for example, must be connected with wall-type components embodied as flow pipes. According to the state of the art, the connection of such components with complex geometries is achieved through high temperature soldering. The high temperature soldering is very complicated and costly and necessitates a high accuracy and therewith a high process expenditure. The high temperature soldering produces difficulties especially when the material pairings of the components that are to be connected with one another are not amenable to soldering. Often, a high re-soldering effort is also necessary, which ultimately makes the connection of components by high temperature soldering expensive. Thus, the connection of components by high temperature soldering is associated with a number of disadvantages.

Beginning from this, the problem underlying the present invention is to provide a novel method for the connecting of components.

This problem is solved by a method for the connecting of components in the sense of patent claim 1. According to the invention, the method encompasses the following steps: a) providing a wall-type component, whereby the wall-type component comprises a sandwich-type structure of two plate-shaped or pipe-shaped elements with a layer of an expandable foamable metal material positioned therebetween; b) providing at least one pipe-shaped or rod-shaped component; c) introducing at least one opening into the wall-type component for the receiving of the or each pipe-shaped or rod-shaped component; d) inserting the or each pipe-shaped or rod-shaped component in a corresponding opening of the wall-type component; e) heating of the arrangement of the wall-type component and the or each pipe-shaped or rod-shaped component while expanding or foaming-up the expandable foamable metal material for the connecting of the or each pipe-shaped or rod-shaped component with the wall-type component.

In the sense of the present invention, a completely novel method for the connecting of components is proposed. Thus, it lies in the sense of the present invention, to provide a wall-type component with a sandwich-type structure, whereby a layer of an expandable foamable metal material is positioned between two plate-shaped or pipe-shaped elements of this sandwich-type structure. At least one opening or recess for the receiving of the rod-shaped or pipe-shaped component, which is to be connected with the wall-type component, is introduced into this wall-type component, whereby after inserting the or each pipe-shaped or rod-shaped component in the corresponding opening, the thusly prepared arrangement is heated while expanding or foaming-up the expandable foamable metal material, in order to rigidly connect the pipe-shaped or rod-shaped component with the wall-type component. Hereby the complex and costly high temperature soldering can be avoided. Moreover, components of which the material pairings are not amenable to soldering can also be connected with one another.

Preferably, the or each pipe-shaped or rod-shaped component is coated with a solder on an end or section with which the pipe-shaped or rod-shaped component is inserted into the corresponding opening of the wall-shaped component. Hereby the quality of the connection is improved.

According to an advantageous further development of the invention, the end or the section of the pipe-shaped component, with which the same is inserted in a corresponding opening of the wall-type component, is closed with a plug or stopper-type element before the insertion of the pipe-shaped component into the corresponding opening of the wall-type component or before the heating and therewith foaming-up expansion, whereby the stopper-type element is removed out of the end or section of the pipe-shaped component after the foaming-up expansion. Hereby, damages of the mostly thin-walled pipe-shaped components during the foaming-up expansion can be avoided.

Preferred further developments of the invention arise from the dependent claims and the following description. An example embodiment of the invention is explained more closely in connection with the drawing, without being limited thereto. Therein:

FIG. 1 shows a cut-out partial cross-section through a wall-type component with a pipe-shaped or rod-shaped component that is to be connected with the wall-type component for clearly representing the inventive method.

In the following, the present invention will be described in greater detail with reference to FIG. 1.

FIG. 1 shows a pipe-shaped component 10, which is to be connected with a wall-type component 11 in the sense of the inventive method. The illustrated pipe-shaped component 10 involves a lance pipe of a heat exchanger, the wall-type component 11 involves a cylinder-shaped flow pipe of the heat exchanger, which comprises a circular profile in the cross-section.

In the sense of the present invention, a wall-type component 11 is provided, which has a sandwich-type structure. In the illustrated example embodiment, the sandwich-type structure is formed by two pipe-shaped elements 12 and 13, whereby a layer 14 of an expandable foamable metal material is arranged between the two pipe-shaped elements 12 and 13. The layer 14 of the expandable foamable metal material is formed by a sintered metal powder and at least one propellant. For this purpose, a metal powder is mixed with a propellant, whereby this mixture of metal powder and propellant is compressed. The compression can be achieved by extrusion or by axial hot-pressing, whereby the expandable foamable metal material exists following the compression. The metal powder can be formed on the basis of an aluminum alloy or titanium alloy or nickel alloy or cobalt alloy or also an iron alloy. Titanium hydride is preferably used as a propellant.

At least one opening or recess is introduced into the wall-type component 11 with the above described sandwich-type structure, whereby a pipe-shaped component 10 is introduced into each one of these openings. After the insertion of the or each pipe-shaped component 10 into the corresponding opening of the wall-type component 11, the arrangement of the wall-type component 11 and the pipe-shaped component 10 is heated, with foaming-up expansion of the expandable foamable metal material of the layer 14, in order to connect the or each pipe-shaped or rod-shaped component 10 with the wall-type component 11. In that regard, the above arrangement is heated to slightly above the melting point of the metal material, so that the metal material is melted, and a gas evolution of the propellant occurs. The foaming-up expansion of the metal material is initiated by the gas evolution of the propellant. The foaming-up expansion is carried out so long until a defined degree of foaming is achieved, which serves for a rigid connection between the components that are to be connected with one another. As soon as this defined degree of foaming is achieved, the foaming-up expansion is ended or terminated in that the arrangement is cooled to below the melting point of the utilized metal powder. Hereby the entire arrangement is stabilized. It is pointed out, that only the layer 14 of the expandable foamable metal material is foamed-up during the heating, the pipe-shaped elements 12 and 13 on the other hand are volume-stable during the heating and are therefore not foamed-up.

While in the example embodiment of FIG. 1, only one pipe-shape component 10 is connected with the wall-type component 11, it is of course possible that a plurality of pipe-shaped components 10 are connected with a wall-type component 11. For this purpose, simply a plurality of openings must be introduced into the wall-type component 11, into which the corresponding pipe-shaped components 10 can then be inserted. It is in the sense of the present invention to coat, with a solder 16, the pipe-shaped component 10 on an end 15 with which the same is inserted into the corresponding opening of the wall-type component 11. During heating of the arrangement, the solder is melted and hereby the quality of the connection between the pipe-shaped component 10 and the wall-type component 11 is improved.

The pipe-shaped components 10 that are to be connected with the wall-type component 11 are usually very thin-walled. In order to avoid damages of the same during the foaming-up expansion, it is proposed in the sense of the present invention, to close, with a plug or stopper-type element (not shown), the end 15 of the pipe-shaped component 10, with which the same is inserted into the respective opening of the wall-type component 11, before the insertion or before the heating and therewith foaming-up expansion. Hereby the ends 15 of the pipe-shaped components 10 are stiffened before the foaming-up expansion, so that damages thereof are avoided. After the foaming-up expansion, the stopper-type element is removed out of the respective end of the pipe-shaped component 10.

The inventive method preferably finds application in the production of heat exchangers, in order to connect lance pipes with cylinder-shaped flow pipes. The inventive method can be utilized everywhere where especially thin-walled pipe-shaped components are to be connected with a wall-type component. 

1. Method for the connecting of components, namely for the connecting of at least one pipe-shaped or rod-shaped component with a wall-type component, with the following steps: a) providing a wall-type component (11), whereby the wall-type component (11) comprises a sandwich-type structure of two plate-shaped or pipe-shaped elements (12, 13) with a layer (14) of an expandable foamable metal material positioned therebetween; b) providing at least one pipe-shaped or rod-shaped component (10); c) introducing at least one opening into the wall-type component (11) for the receiving of the or each pipe-shaped or rod-shaped component (10); d) inserting the or each pipe-shaped or rod-shaped component (10) in a corresponding opening of the wall-type component (11); e) heating of the arrangement of the wall-type component (11) and the or each pipe-shaped or rod-shaped component (10) with foaming-up expansion of the expandable foamable metal material for the connecting of the or each pipe-shaped or rod-shaped component (10) with the wall-type component (11).
 2. Method according to claim 1, characterized in that the or each pipe-shaped or rod-shaped component (10) is coated with a solder (16) on a section or end (15) with which the same is inserted into the corresponding opening of the wall-type component (11). 3-9. (canceled)
 10. Method according to claim 1, characterized in that the two plate-shaped or pipe-shaped elements (12, 13) of the wall-type component (11) are volume-stable during the heating and are not foamed-up.
 11. Method according to claim 1, characterized in that the layer (14) of the expandable foamable metal material positioned between the two plate-shaped or pipe-shaped elements (12, 13) is formed of a sintered metal powder and at least one propellant.
 12. Method according to claim 11, characterized in that the metal powder is formed on the basis of an aluminum alloy or titanium alloy or nickel alloy or cobalt alloy or iron alloy.
 13. Method according to claim 11, characterized in that the propellant is formed by titanium hydride.
 14. Method according to claim 1, characterized in that a section or an end (15) of the pipe-shaped component (10), with which the same is inserted in a corresponding opening of the wall-type component (11), is closed with a stopper-type element before the insertion of the pipe-shaped component (10) in the corresponding opening of the wall-type component (11) or before the heating and therewith foaming-up expansion, whereby the stopper-type element is removed out of the section or end (15) of the pipe-shaped component (10) after the foaming-up expansion.
 15. Method according to claim 1, characterized in that the foaming-up expansion is terminated by cooling upon reaching a defined degree of foaming.
 16. Method according to claim 1, characterized in that a cylinder-shaped flow pipe of a heat exchanger is provided as wall-type component (11), and that lance pipes of a heat exchanger are provided as pipe-shaped components (10), which are connected with the flow pipe. 